An ignition interlock device is a breath-testing device that is installed in a vehicle and is connected to the ignition, horn and headlights. To start the vehicle, a driver must blow into the device without registering a blood alcohol concentration (BAC).

Missouri law requires any person guilty of a second or subsequent intoxication-related traffic offense to install an ignition interlock device on any vehicle they operate before reinstating driving privileges.

Each ignition interlock provider is responsible for reporting ignition interlock compliance to the Department of Revenue and/or the court-ordered supervising authority.

If you are required to have an ignition interlock device installed, call the manufacturers listed below to obtain information regarding installation, pricing and locations around the state. Make sure that the device you have installed is one of the approved devices listed below.